Pyridinium Bromide Derivatives as Corrosion Inhibitors For Mild Steel in 1M H2SO4

In this work, we present a study on the synthesis and characterization of a new series of pyridinium salts, namely 4-(2- ((1E,2E)-3-phenylallylidene)hydrazine-1-carbothioamido)-1-propylpyridin-1-ium bromide, P1; (E)-3-(2-(4-(dimethylamino) benzylidene)hydrazine-1-carbothioamido)-1-ethylpyridin-1-ium bromide, P2; (E)-3-(2-(4-(dimethylamino)benzylidene) hydrazine-1-carbothioamido)-1-propylpyridin-1-ium bromide, P3; using spectroscopic techniques such as IR and 1H NMR, as well as the evaluation of their ability to inhibit mild steel corrosion in 1 M H2SO4 at 20 degrees C using weight loss techniques and scanning electron microscopy. The investigation yielded that the Schiff bases and Pyridinium salts derivatives were successfully synthesized as suggested by the characterization results. In 1 M H2SO4 solution, Pyridinium salts derivatives showed substantial inhibitive activities for mild steel corrosion. Their inhibition efficiencies increased with increasing concentration of inhibitors. The adsorption of the studied compounds on the surface of mild steel follows the Langmuir isotherm model.